Error when trying to find closest feature using buffer

BrianHumphries1

Hello,

I'm having trouble with an attribute rule expression in ArcGIS Pro 2.9. I'm trying to find the nearest hydrant within 50 feet of a water sample site using a buffer, but I keep getting errors that say "field not found" or "expected convertible to geometry".

Here's the code I'm using:

var hydrantLayer = FeatureSetByName($datastore, 'SDEP.SDEADMIN.w_watr_hydrant');
var buffer = Buffer($feature.Shape, 50, 'feet');
var closestHydrant;
var closestDistance = 9999999;
var intersectedFeatures = Intersects(hydrantLayer, buffer);
for (var i in intersectedFeatures) {
  var feature = intersectedFeatures[i];
  var distance = Distance($feature.geometry, feature.geometry, 'feet');
  if (distance < closestDistance) {
    closestDistance = distance;
    closestHydrant = feature;
  }
}
if (closestHydrant) {
  return closestHydrant['UID'];
} else {
  return null;
}

 

I've tried changing "geometry" to "Shape" and using FeatureSetByName to reference the hydrant layer, but I keep getting errors. Can anyone help me figure out what I'm doing wrong?

Thank you in advance for your help!

 

JohannesLindner

Multiple problems here:

 

line 2: Buffer() takes a Feature or a Geometry, you're giving it a field value.

Buffer($feature, 50, 'feet');

 

line 6&7: If you loop through a Featureset, the loop variable is actually the Feature:

for(var f in fs) {
    Console(f.Field)
}

 

line 8: Distance() takes tow Features or Geometries. You're supplying a non-existing field.

var d = Distance($feature, other_feature, "feet")

 

line 14: this looks like you're used to the truthy values of Python. This doesn't work with Arcade, you have to check actual booleans.

if (closestHydrant != null) {

 

throughout the expression: You're using function names as variable names (Buffer, Feature, Distance). This is a very bad practice, because you're overwriting these functions.

After line 2, you can't call Buffer() anymore, because that name is now bound to a polygon. This isn't a problem in your expression, but you have the same thing going on with Distance(), and you try to call that in a loop, which will fail.

 

var hydrantLayer = FeatureSetByName($datastore, 'SDEP.SDEADMIN.w_watr_hydrant');
var b = Buffer($feature, 50, 'feet');
var closestHydrant;
var closestDistance = 9999999;
var intersectedFeatures = Intersects(hydrantLayer, b);
for (var f in intersectedFeatures) {
  var d = Distance($feature, f, 'feet');
  if (d < closestDistance) {
    closestDistance = d;
    closestHydrant = f;
  }
}
if (closestHydrant != null) {
  return closestHydrant['UID'];
}
return null;